1 files changed, 4 insertions, 1 deletions
diff --git a/components/script/dom/documentorshadowroot.rs b/components/script/dom/documentorshadowroot.rs
index c814b75cfda..37464a2f1d4 100644
--- a/components/script/dom/documentorshadowroot.rs
+++ b/components/script/dom/documentorshadowroot.rs
@@ -303,7 +303,10 @@ impl DocumentOrShadowRoot {
         root: DomRoot<Node>,
     ) {
         debug!("Adding named element {:p}: {:p} id={}", self, element, id);
-        assert!(element.upcast::<Node>().is_connected_to_tree());
+        assert!(
+            element.upcast::<Node>().is_in_a_document_tree() ||
+                element.upcast::<Node>().is_in_a_shadow_tree()
+        );
         assert!(!id.is_empty());
         let mut id_map = id_map.borrow_mut();
         let elements = id_map.entry(id.clone()).or_default();